Guarding and guiding attachment for tools



N .25, 1930 s. F. SHORT n 1,782,448

GUAHDING AND GUIDING ATTACHMENT FOR TOOLS Filed Nov. 15, 192e za 2a .1 Z7 27 55 ticularly to a guardin and blade -andhaving a.. threaded engagement" connefntion` with Patented N ov. 25,r 1930 UNITED STATES PATENT OFFICE SAMUEL FRANCIS SHORT, OF LA GRANGE, ILLINOIS, ASSIGNOR TO WESTERN ELECTRIC .l

COMPANY, INCORPORATED, OF NEW' YORK, N. Y., A CORPORATION OF NEW YORK eumnvennn GUIDING ATTACHMENT non Toons Application led. November 15, 1926. Serial No. 148,393;

This invention relates `to guarding and guiding attachments for tools,"and more parguiding attachment forrotatable too s.

In rotatable tools,.such as manually op?.

ator, which might possiblyv result `from such amovement. 'I Y,

The primary object of this invention isv to provide a' simple land inexpensive attachment for the hereinbefore described purpose which maybe readily, adjustably andpositively attachedinoperative position upon a tool.

In accordance with the general features` of this inventionthere is provided in `one embodiment thereof, as 'applied to a blade of a manually operablegfscrew driving tool,

a sleeve adapted tofreceive the tang of Athe blade and the headof the screw to be operated, a spring jaw chuck ,surrounding the with the sleeve being provided `for adjust-f abl and positively attaching the vguarding an guiding sleeve in a predetermined operative position upon theblade. l Other objects and 'advantages of this invention `will more fully appear from thega'c compari-ying detailed description taken 'in t the 4 accompanying drawings, in which Fig. 1 isa view, partly in section, of a man ually operable tool holder carrying ascrew driving blade having a guard embodying the features of this invention, `operatively attached thereto; V n

Fig. 2ois an enlarged :fragmentary view thereof, partly in vertical section,showin the combined guard and guide and the tang of the blade in operative positionwith respect to a round headed screw;

'holder is illustrated, the 4numeral 10 represents a handle, preferably of wood, which is shouldered at one end to receive a metal ferrule 11. The ferruled, end of the handle is provided with a bore 12 for the reception of the shank of a multi-spring jaw chuck 13,

which with the ferrule 11 is secured against relative rotation within the handle 10 by a pin'14 extending through all three members. The chuck. 13 at its outer end is slotted to form a plurality of jaws 15 provided with l-external screw threads for engaging interior threads formed in a sleeve 16, the sleeve having a hexagonal `shaped exterior surface upon an enlarged end thereof to facilitate the threading thereof onto the jaws 1b.v The sleeve 16 is provided with an internal tapered circular' surface 18 adapted toi engage a lshouldered unthreaded portion 19 of each of' thejaws 15 toV contract the latter suiiciently to clamp a tool,in the present instance ascrew driving blade 20, ag'ainst longitudinal displacement within af bore 21 of the. chuck 13; The inner end Yof the blade 20 extending into the bore 21 of the chuck 13 is provided with a tongue 22 which extends 'into a notch formed in the shank of the chuck at the inner end of the bore thereof, thus providing means for securing the blade againsty relative rotation uponthe chuck when rotatingV a screw-l The operative end yof the blade 20`is beveled from opposite sides to form atang 23 (Fig. 2) for insertion in the usual transverse slot formed in scesvV heads, that portion ofthe blade intermediate the tongue 22'and the tang being circular and uniform in cross-section throughout its v length.V 'l j Upon the operative end ofthe blade20 isa chuck 25 provided with four spring jaws 26, screw threaded as indicated at 2'( upon their upper exterior surfaces and integrally connected together by a sleeve portion 28 (Fig. 2), the internal diameter of which is such that it is freely slidable upon the blade when the jaws are not contracted into gripping engagement with the peripheral surface of the blade, the jaws being tapered toward their free ends u on their external surfaces. The exterior sur ace of the portion 28 of the chuck 25 is hexagon shaped as indicated by the numeral 31 for the pur ose of facilitating the rotation of the chuc when contracting the jaws 26 in a manner to be described hereinafter. Surrounding theperiphery of the chuck 25 for the greater portion of its length is a guard and guide in the form of a sleeve 82 provided with an internally ta pered surface 33 intermediate its ends and with internal screw threads 34 at its upper end (Fig. 2) for engagement with the threads 27 upon the jaws 26 of the chuck. The upper end of the sleeve 32 is also provided with a hexagon shaped exterior surface 35, the purpose of which will be made apparent hereinafter. The extreme free end of the sleeve 32 is tapered upon its exterior surface but is not tapered upon its internal surface, the internal diameter thereof being sufficient to permit the blade 2O to pass freely therethrough and also to receive the head of the particular screw with which it is to be operatively associated, as clearly indicated in Fig. 2.

In using the guard hereinbefore described in connection with a round headed screw 38 (Fig. 2), the sleeve 32 is adjusted longitudinally upon the screw driving bla-de 20 until its lower annular surface is slightly above the bottom surface of the screw head and with the tang 23 positioned at the bottom of the slot formed in the head of the screw. In this position of the guard and guide upon the blade 20, the lower annular surface of the sleeve 32 will not engage the surface against which the bottom surface of the screw head rests when the screw is in its full securing position. When the guard is thus correctly positioned it is securely and positively retained thereat by the contraction of the jaw 26 against the peripheral surface of the blade 20. This is accomplished in the following manner: The hexagon shaped end of the sleeve 32 is gripped is a vise or other suitable means adapted to hold it stationary while the hexagon s aped end 31 of the chuck 25 affords a grip for a wrench or other means whereby the chuck ma be threaded into the sleeve 32, the internal y tapered surface 33 of the sleeve causing a'contraction of the clutch jaws 26 against the eriphery of the blade 20 as the tapered sur aces of the jaws move therealong and thus positively clamp the sleeve in a definite operative position and insuch a manner that it cannot be accidentally displaced. As thus assembled and in actual use it will be apparent that upon bringing the tang 23 of the screw driving blade 20 into operative relation with the slot of the screw, the sleeve 32 which extends from the tang and is of substantially the same diameter as the head of the screw will serve to guide the latter into axial alignment within the slot of the screw and during the rotation thereof prevent any lateral movement thcrev between which would cause/the tang to become displaced from the slot and possibly injuring adjacent surfaces of the work in which the screw is being rotated, the tool, the screw or the operator. j f

Figs. 4 and 5 illustratel the use of the guard and guide in connection` with a countersunk flat headed screw 39. Although the sleeve 32 in this instance does not serve to actually prevent lateral movement between the tang 23 and the screw slot, it does tend to minimize injury to surrounding surfaces, the tool or the operator as will be apparent, due to the greater area of the sleeve 32 as compared to the comparatively sharp end surface of the tang. The tang of the blade 20, as illustrated in connection with the screw 39, has been beveled upon opposite ends as indicated at 40 for the purpose of completely engaging the parallel spaced walls of the screw slot, thus providinoc a maximum bearing surface.

Although die invention has been illustrated and described in connection with a manually operable screw driving tool7 it will be understood that it may be applied equally well to power driven screw driving mechanisms and also to other types of tools wherein an operative end of the tool is to engage a complemental formation of an article.

What is claimed is:

1. In combination with a screwdriver having a tang and a blade of constant cross-section, a threaded sleeve normally slidable on `the blade and provided with a resilient extension positioned adjacent the blade, and a guard having an upper portion threadedly engaging the sleeve, a lower ortion having its inner diameter substantially equal to the width of the tang and designed to surround the tang to provide a guard and guide therefor, and an intermediate portion having a tapered inner surface designed to force the extension into fixed frictional engagement with the blade when the guard is moved lon- -gitudinally of the sleeve, said surface tapering to a smaller diameter than that of the blade of the screw-driver so as to bind on the end thereof and limit the upward adjustment of the guard.

2. In combination with a screw-driver having a blade of constant cross-section terminating in a tang, a threaded sleeve normally slidable on the blade and provided with a resilient extension positioned adjacent the blade, and a guard having threaded engagement with the sleeve and provided with a portion designed to surround the tang l) tl lll) Y Y l A 1,782,448

of the screw-driver and also provided with a tapered portion designed to contact with the extension and bring it into fixed frietional engagement with the blade upon rotation of the guard relative to the sleeve, said surface taperin to a smaller diameter than that of the bla e of the screw-driver so as to bind on the end thereof and limit the upward adjustment of the guard. lo In Witness whereof, I hereunto subscribe my name this 29th day of Oct. A. D., 1926.

SAMUEL FRANCIS SHORT. 

